A liquid crystal display panel is a main component of a liquid crystal display device, including an array substrate, a color filter substrate, and liquid crystal sealed between the array substrate and the color filter substrate. The liquid crystal is applied to the alignment layer so as to be arranged in a specified direction.
FIG. 2 shows a partial cross section of the edge of existing conventional LCD panel. The LCD panel includes an array substrate and a color filter substrate. The color filter substrate includes a top plate 10, and a top electrode 30 is arranged on the top plate 10. The array substrate includes a bottom plate 20, and a bottom electrode 40 is arranged on the bottom plate 20. Alignment layers 50 are respectively coated on the top plate 10 and the bottom plate 20. In FIG. 1, the line from A to A′ represents the active edge 101 of the active area; the line from B to B′ represents the alignment edge 51 of the alignment layer 50. Considering the application accuracy of the alignment layers 50 and nonuniform thickness at edges of the alignment layers 50, a space X must be left between the active edge 101 and the alignment edge 51; otherwise, poor liquid crystal alignment or mura may occur at the edge of the active area.
In FIG. 1, Y represents the application range of a sealant 60, namely the sealant area. The sealant 60 contains spacers for supporting the cell gap. Z represents a space in which an Au ball 70 can be applied, namely a transfer pad. Generally, in a common vertical alignment or twist nematic display mode, the top plate 10 is provided with the transparent top electrode 30. In fact, however, printed circuit board (PCB) or IC is bonded to the bottom plate 20. Thus, signals of the bottom electrode 40 must be transmitted to the top electrode 30 of the top plate via the Au ball 70.
In general, the resistance of the alignment layer is very high, so when the top electrode or the bottom electrode in the transfer pad is covered by the alignment layer, the Au ball can not effectively transmit signals of the bottom electrode to the top electrode, and the display of the LCD panel will be abnormal. Therefore, as shown in FIG. 1, to ensure that the Au ball 70 in the transfer pad Z can operate effectively, the edge of the alignment layer 50 must be separated from the transfer pad Z, and a wide frame is usually left at the edge of the plate (the frame represents the width of the inactive area of the plate) to prevent the alignment layer 50 from covering the transfer pad Z, resulting in that the top electrode and the bottom electrode cannot be conducted through the Au ball 70.